Pneumatic apparatus for blanching heated or roasted peanuts

ABSTRACT

New apparatus and concept for removing skins from peanuts is disclosed. Peanuts in a batch operation are continuously forced into the air stream by the design of an internal retainer screen and a baffle formed by a second screen. The stripping action of the air and the rubbing of the kernels along the wall surfaces of an upper and a lower retainer screens efficiently separate the skins from the meats, and the skins removed from the batch by vacuum.

United States Patent 1 Barnes, Jr. et al.

[451 May 7,1974

[54] PNEUMATIC APPARATUS FOR 2,667,197 1/1954 G1,, 99/519 BLANCHING HEATED 0 ROASTED 3,480,057 11/1969 Wilhelm 99/584 PEANUTS 3,561,515 2/197] Nahm 99/519 [75] Inventors: Phillip C. Barnes, Jr., Bronwood;

Charles Holadayi Albany i Primary Examiner-Robert W. Jenkins [73] Assignee: The United States of America as represented by the Secretary of Agriculture, Washington, DC.

22 Filed: Mar. 17, 1972 [57] ABSTRACT [21] Appl 235694 New apparatus and concept for removing skins from peanuts is disclosed. Peanuts in a batch operation are [52] us. Cl. 99/518 continuously forced n he r str am y the design [51] Im. Cl A23] 1/18 of an al r tain r s r en and a affl formed by a [58] Field of Search 99/584, 518, 519, 525, second screen. The stripping action of the air and the 99/616, 617, 629, 632, 472, 473, 474, 477, rubbing of the kernels along the wall surfaces of an 2334 2335, 528 upper and a lower retainer screens efficiently separate the skins from the meats, and the skins removed from [56] References Cited he bat h by vacuum.

UNITED STATES PATENTS 98,975 1/1870 Jones 99/519 1 Claim, 1 Drawing Figure 1 PNEUMATIC APPARATUS FOR BLANCHING HEATED OR ROASTED PEANUTS A non-exclusive, irrevocable, royalty-free license in the invention herein described throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to food processing machinery. More specifically, this invention relates to a new apparatus and method for removing skins from peanuts.

In the prior art the literature teaches the removal of the skin of peanuts by rubbing between two rubber belts, slicing with knives, soaking in water, and treating with alkaline solutions. The known machines and processes have proven to be not entirely satisfactory for small size operations. A significant disadvantage of the prior art is the wear of moving parts and the daily maintenance requirements.

The main object of this invention is to provide an apparatus suitable for small scale blanching operations.

Another object of the present invention is to provide an improved machine, one without moving parts within the blanching compartment.

A third objectof this invention is to provide a machine which can blanch small samples of peanuts.

A fourth object of this invention is to provide a machine that may be operated atdifferent lengths of time thereby allowing the peanuts to be exposed to the blanching for controllably varying quantities of time.

A fifth object of this invention is to provide an apparatus which requires little or no maintenance.

A heretofore proposed method of blanching concerns the heating and rubbing between brushes or ribbed-rubber belting. This process is not adaptable to small batches of peanuts (IUD-1,000 grams) and has several moving parts. The brushes and ribbed-rubber belting need periodic replacing in order to maintain efficient blanching. It has also been proposed to blanch peanuts by water which involves cutting the skins of the individual kernels longitudinally as they roll between sharp stationary blades then running the kernels through a hot water spray to loosen the skins. The skins are removed on a knobbed conveyor as the kernels pass under an oscillating canvas-covered pad. The kernels are subsequently dried by a current of 120 F. air. Water blanching is a costly process involving numerous moving parts and the availability of warm water and warm air. It is not adaptable to small batches of peanuts (100-1 ,000 grams). Spin blanching is an adaptation of the water blanching method wherein the hot water spray is bypassed and conveyed directly to the driers where they are quickly dehydrated at a lower than roasting temperature to loosen the skins. The disadvantages of this adaptation are similar to the water blanching process.

The apparatus of the present invention can best be described by making reference to the FIGURE, which illustrates the basic idea involved in the new concept of this invention. In describing the illustrated apparatus 'specific terminology serves the purpose of facilitating rapid comprehension; however, it is notintended for the invention to be limited to the specific terms employed here, since all technical equivalents would operate in a similar manner to accomplish similar goals.

The FIGURE is a schematic elevation view of the apparatus of this invention.

The specific embodiment of this invention, as shown in the FIGURE, indicates that there is a first and a second conical structure, the one in an inverted position with respect to the other. These conical structures can be thought of as an upper funnel 3, and a lower funnel 5. These conical structures have cylindrical extensions so that the extension of the upper funnel would be downward, and the cylindrical extension of the lower funnel would be upward. The lower funnel 5 would be in a normal funneling position while the upper funnel 3 would be in an inverted position during operation. The flanges of both funnels are designated by the terms upper flange 9 and lower flange 10 which when assembled are provided with rubber seals 4. Vacuum exhaust apperture l is connected to a small, hand-type vacuum device. The vacuum is required to remove dust and skin particles loosened during processing, and to maintain a tight seal between the upper and lower funnels during operation. The upperv funnel has a retainer screen (/8 inch hardware cloth is suitable) which keeps the peanuts separated from the trash. The circular retainer screen 2 is secured to the upper funnel 3 at the point where the conical surface meets the cylindrical surface. The circular retainer screen 2 has a planner configuration.

Lower funnel 5 is designed to operate, normally, with lower flange 10 opening upward, so that lower funnel 5 will operate in a funneling-by-gravity position, with its apex downward. Lower flange 10 provides support for a conical retainer screen 6, which is oriented in the same manner as the lower funnel 5 but with a more acute configuration than the lower funnel. A as inch air jet nozzle 7 is inserted upward through the apperture designated as intake apperture 8. The nozzle is 'designed to be connected to a source of compressed air with a static pressure of about '50 pounds per square inch.

In operation, 250 grams of unblanched peanuts previously heated to about 400 F. for 25-30 minutes are placed in lower retainer screen 6 and the top funnel 3 is set in place so that the rubber seals 4 are matched. Turn on the vacuum cleaner and after a seal is established between the upper and lower funnels, turn on the compressed air. The peanuts immediatelystart a tumblingmotion rubbing against the retainer screens 2 and 6. This action, together with the stripping action of the air jet 7, removes the skins. After two minutes turn off the air and the vacuum. Remove the blanched nuts from the lower retainer screen.

A more detailed description indicating the results obtained using the apparatus and concept of this invention has been published by P. C. Barnes, et al;, in the J qqryataf.Endgam lq qm 3.61. 1).

We claim: I

1. An apparatus for blanching heated or roasted peanuts in batch quantities, said apparatus energized entirely by the movement of air, said apparatus consisting of these components assembled to operate as a unit structure;

a. an upper funnel component comprising a conical sheet metal structure which is continuous with a cylindrical structure at its conical base and having an apperture at its apex from which an exhaust tube of about inch diameter extends and onto which a vacuum source is attached, said component designed to function with its apex upward,

b. a circular retainer screen of planar configuration and constructed from inch hardware cloth, for constraining the peanut meats, the said retainer screen secured at the circumference line inside the upper funnel of (a) where the conical structure meets the cylindrical structure,

0. a lower funnel component comprising a conical sheet metal structure of dimensions and design equal to the upper funnel of (a) but designed to function in a gravity-funneling position with its apex downward,

d. a conical retainer screen made of about inch hardware cloth to support a batch charge of peanuts and simultaneously allow the passage of a jet stream of air which is directed upwards, said conical retainer screen having its apex downward, and

said conical retainer screen secured with its apex downward inside the lower funnel component of e. an air jet nozzle, which is inserted at the apex of the lower funnel component of (c) and capable of handling a jet stream of air of about 50 pounds per square inch pressure,

f. a vacuum source of small capacity,

g. an air source of at least 50 pounds per square inch pressure, and

h. a rubber seal which fits at the open end of each funnel to provide an air tight joining of the open ends (the flanges) of the component funnels when these are assembled for operation of the apparatus. 

1. An apparatus for blanching heated or roasted peanuts in batch quantities, said apparatus energized entirely by the movement of air, said apparatus consisting of these components assembled to operate as a unit structure; a. an upper funnel component comprising a conical sheet metal structure which is continuous with a cylindrical structure at its conical base and having an apperture at its apex from which an exhaust tube of about 3/8 inch diameter extends and onto which a vacuum source is attached, said component designed to function with its apex upward, b. a circular retainer screen of planar configuration and constructed from 1/8 inch hardware cloth, for constraining the peAnut meats, the said retainer screen secured at the circumference line inside the upper funnel of (a) where the conical structure meets the cylindrical structure, c. a lower funnel component comprising a conical sheet metal structure of dimensions and design equal to the upper funnel of (a) but designed to function in a gravity-funneling position with its apex downward, d. a conical retainer screen made of about 1/8 inch hardware cloth to support a batch charge of peanuts and simultaneously allow the passage of a jet stream of air which is directed upwards, said conical retainer screen having its apex downward, and said conical retainer screen secured with its apex downward inside the lower funnel component of (c), e. an air jet nozzle, which is inserted at the apex of the lower funnel component of (c) and capable of handling a jet stream of air of about 50 pounds per square inch pressure, f. a vacuum source of small capacity, g. an air source of at least 50 pounds per square inch pressure, and h. a rubber seal which fits at the open end of each funnel to provide an air tight joining of the open ends (the flanges) of the component funnels when these are assembled for operation of the apparatus. 